高分辨率双侧向测井仪理论设计的新方法

Theoretical Design on High Resolution Dual-logging Tool

油田开发后期要求测井曲线具有较高的分辨率 ,现有双侧向测井仪器的测量方式和电极结构用于高分辨率仪器时 ,由于主监控电路的增益不能无限增大 ,使仪器的测量精度降低很多。为此 ,探讨了两种解决方案 :一是改变主电极系的结构 ,将主电极与一对监督电极互换 ,解决了原电极结构存在的因电极距缩短导致监督电极间距缩短的问题 ,降低了对仪器增益的要求 ;二是不改变电极的相对位置 ,根据电位叠加原理实现仪器的数值软聚焦 ,以其代替传统的电路聚焦 ,这种聚焦方式不要求监督电极剩余电位差为零 ,降低了仪器电路实现的难度。在研究中 ,综合考虑了电子线路的测量精度、仪器测量方式等因素的影响 。

The electric circuit monitor method used in conventional dual laterolog tool is invalid in a new type high resolution tool due to the limitation of electric gain in the main monitoring loop. Two ideas are discussed in this paper to avoid the problems so that the theoretical design of high resolution dual laterolog tool can be applicable.One is achieved by changing the electrod location of A 0 and M 1 (M 1 ′),another is achieved through numerical software synthetic focusing method.